[omnibox] Add Ablate HQP Cache to fieldtrial_testing_config.json.

The Canary/Dev experiment was successful, and we are adding this ablate
flag to the fieldtrial_testing_config.json now to proceed to the Beta
experiment.

Bug: 1141539
Change-Id: I8cda087190af3a2ab9db5eb93606010208b4484f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2616239Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841714}

testing/variations/fieldtrial_testing_config.json

@@ -5022,6 +5022,7 @@
                         "OmniboxDisplayTitleForCurrentUrl",
                         "OmniboxDynamicMaxAutocomplete",
                         "OmniboxEntitySuggestionsReduceLatency",
+                        "OmniboxHistoryQuickProviderAblateInMemoryURLIndexCacheFile",
                         "OmniboxLocalZeroSuggestAgeThreshold",
                         "OmniboxLocalZeroSuggestFrecencyRanking",
                         "OmniboxMaxURLMatches",
@@ -5061,6 +5062,7 @@
                     "enable_features": [
                         "OmniboxAdaptiveSuggestionsCount",
                         "OmniboxCompactSuggestions",
+                        "OmniboxHistoryQuickProviderAblateInMemoryURLIndexCacheFile",
                         "OmniboxLocalZeroSuggestAgeThreshold",
                         "OmniboxLocalZeroSuggestFrecencyRanking",
                         "OmniboxMaxURLMatches",